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Richard Niemiec

"Oracle Database 10g Performance Tuning Tips & Techniques"

. .
TOOL_RENTALS TOOL_RENTALS_P4 TOOL_RENTALS_P4_S8 PRD04
32 rows selected.
At the logical partition level, we still need to query DBA_TAB_PARTITIONS to obtain the
range values, as you can see in the following query:
SQL> select table_name, partition_name,
2 subpartition_count, high_value
3 from dba_tab_partitions
4 where table_name = 'TOOL_RENTALS';
TABLE_NAME PARTITION_NAME SUBPARTITION_COUNT HIGH_VALUE
---------------- ------------------- ------------------ -------------
TOOL_RENTALS TOOL_RENTALS_P1 8 101
TOOL_RENTALS TOOL_RENTALS_P2 8 201
TOOL_RENTALS TOOL_RENTALS_P3 8 301
TOOL_RENTALS TOOL_RENTALS_P4 8 MAXVALUE
4 rows selected.
Also note that either the partition name or subpartition name can be specified to perform
manual partition pruning, as in these two examples:
select * from oe.tool_rentals partition (tool_rentals_p1);
select * from oe.tool_rentals subpartition (tool_rentals_p3_s2);
In the first query, a total of eight subpartitions are searched, TOOL_RENTALS_P1_S1 through
TOOL_RENTALS_P1_S8; in the second query, only one out of the 32 total subpartitions is searched.
Using Composite Range-List Partitioning Similar to composite range-hash partitioning,
composite range-list partitioning uses range partitioning to divide rows first using the range
method and then subpartitioning the rows within each range using the list method. Composite
564 Oracle Database 11g DBA Handbook
range-list partitioning is good for historical data to place the data in each logical partition, further
subdividing each logical partition using a discontinuous or discrete set of values.


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